NB2 1-2 Flashcards
Boundaries of the posterior triangle
trapezius muscle
sternocleidomastoid m.
clavicle
Boundaries of the anterior triangle
midline
sternocleidomastoid m
mandible
muscles of the floor of the posterior triangle
splenius capitus
levator scapulae
posterior scalene (C3-C7) middle scalene (C3-C7) anterior scalene (C3-C7)
omohyoid
divides the posterior triangle into the occipital and subclavian triangles
Cervical plexus
ventral rami of spinal nerves C1-C4
The cutaneous branches of the post. triangle are:
lesser occipital (C2) greater auricular (C2,C3) transverse cervical (C2,C3) supraclavicular (C3,4)
CN XI and the post triangle
supplies the SCM and trapezius
also subdivides the post triangle into carefree (above) and careful (below) triangles
path of the hypoglossal nerve (CN XII)
- exits skull through hypoglossal canal and descends medially
- passes between ICA and IJV and hooks around occipital n.
- passes deep to digastric and stylohyoid mm.
- disappears deep to mylohyoid m; to tongue
contents of the carotid sheath
internal jugular v.
common carotid a.
vagus nerve
subdivisions of the anterior triangle
- submental triangle
- submandibular (digastric) triangle
- carotid triangle
- muscular triangle
carotid sinus
dilated portion at the proximal part of the ICA
contains baroreceptors to monitor BP
innervated by branches of CN IX
carotid body
cluster of cells near the carotid sinus
contains chemoreceptors to monitor blood chemistry
innervated by CN IX and X branches
thyroid gland
2 lobes are connected by the isthmus (anterior to the 2nd and 3rd tracheal cartilages)
A. supply:
superior and inferior thyroid A.
venous drainage:
superior, middle, and inferior thyroid V.
muscles of the face generally
develop from the 2nd pharyngeal arch
innervated by CN VII ( facial nerve)
action:
facial expression
sphincters around eyes and mouth
Orbicularis oculi
orbital part:
surrounds each orbit
closes eye forcefully
palpebral part:
located in eyelids
closes eye gently
Corrugator supercilii
deep to the eyebrows
draws the eyebrow down and medial
wrinkles the skin of the nose when frowning
nasal group of facial muscles
- nasalis
transverse part - compresses the nares
alar part - opens the nares - procerus
inserts into the skin of the forehead between the eyebrows
draws medial border down; wrinkles the superficial skin to the nasal bone
active during frowning
- depressor septi nasi
arises from maxilla and inserts into nasal septum
widens the nares by pulling nose down
Platysma, auricular muscles, stylohyoid, occipitofrontalis, posterior belly of digastric
also derived from the 2nd pharyngeal arch
innervated by the facial nerve
Occipitofrontalis
occipitalis:
innervated by posterior auricular branch of CN VII
frontalis:
innervated by temporal branch of CN VII
action:
moves the scalp, wrinkles the forehead, and raises eyebrows
separated by epicranial aponeurosis
how does the facial nerve exit the skull
motor portion of CN VII will exit the skull via the stylomastoid foramen
the 5 branches of the facial nerve?
- temporal
- zygomatic
- buccal
- marginal mandibular
- cervical
parotid gland (structures that pass through) location?
location: anterior to lower half of the ear
- facial nerve
- ECA and its branches
- retromandibular v.
parotid gland innervation and blood supply
blood:
superior temporal
posterior auricular
innervation:
sensory: auriculotemporal nerve (V3)
secretomotor: CN IX, otic ganglion, CN V3
parotid duct
opens opposite 2nd upper molar tooth
submental lymph nodes
drains from medial part of the lower lip and chin
submandibular nodes
drain medial corner of orbit external nose medial cheek upper lip lateral of lower lip
pre-auricular nodes and parotid nodes
drain eyelids, external nose, lateral cheek
layers of the scalp
scalp proper:
skin - hair follicles
connective tissue (dense)
aponeurotic layer- contains muscle
loose connective tissue:
danger zone - infections can spread by emissary vein and cranium
pericranium
caput succedaneum
soft superficial swelling just under the skin
seen at the time of birth
due to edema
Subgaleal hemorrhage
hemorrhage between the aponeurotic layer
and periosteum
develops few hours after delivery
can involve large amount of blood
Cephalohematoma
hemorrhage between the periosteum and
bone
usually appears within 24 -72hrs after delivery
may take weeks to resolve
does not cross suture lines since periosteum
fuses (confined to individual bones)
innervation of the scalp anterior to the ears
supratrochlear (CN V1)
supraorbital (CN V1)
zygomaticotemporal (CN V2)
auriculotemporal (CN V3)
innervation of the scalp posterior to the ears
‣ great auricular
‣ lesser occipital
‣ greater occipital
‣ third occipital
lymph drainage of the occipital region of scalp
occipital nodes
upper deep cervical nodes
lymph of upper scalp
posterior to vortex:
mastoid nodes
upper deep cervical
anterior to vortex:
pre-auricular
parotid nodes
forehead:
submandibular nodes
